#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
int addzy(int a, int b)
{
	return a + b;
}
int minzy(int a, int b)
{
	return a - b;
}
int mainzyb()
{
	int a, b, c;
	scanf("%d %d %d",&a,&b,&c);
	int (*m[3])(int, int) = { NULL,addzy,minzy };
	if (c == 1 || c == 2)
	{
		printf("%d", m[c](a,b));
	}
	printf("\n");
	return 0;
}